Numerous plumbing connections between supply conduits and valves or faucets are known in the art. To provide a good fluid tight seal, various washers, adhesives, or other materials are generally required in fitting or coupling the supply conduit to the faucet.
One type of connection between a metal tubular water supply and a faucet body requires brazing or welding along with the use of a transitional member, such as rubber, to accomplish sealing and mechanical attachment. Metal parts, brazing, and assembly are becoming increasingly costly. Also, high temperatures utilized in the brazing process badly discolors the metals involved and usually makes it necessary to subsequently clean the parts with acid or alkaline.
When connecting metallic supply lines to a faucet with a plastic mounting body, sealing and mechanical attachment becomes complex in the sense that copper tubes cannot be brazed to plastic. In such cases copper tubes are brazed to a plate of brass, which in turn is screwed to the plastic mounting body of the faucet using a secondary gasket to provide a seal.
A particular problem is encountered in making a plumbing connection when the supply conduits are made from thin, flexible plastic tubing which are easily deformable and in addition, possess a rather low coefficient of friction. To assure a good mechanical connection, some prior designs have suggested the use of metallic fittings which use a rubber gasket seal against the outside plastic pipe diameter and an internal metal stiffener.